Cleaning Oiii filter?

[mylatestwhim]

Hi just bough the above used and have a coupe of questions.

1. What is the best way to clean them?
   
2. Last night I was viewing something with nebulocity (sp?) and tried the filter to be met with blackness and a reflection of my eyeball. It was screwed on to the 40mm EP properly so cant have been on wrong? Any ideas??
   

thanks,

Andrew

[Merlin66]

baader optical cloth will clean most optical surfaces, but I don't think your filter is dirty... what you describe is pretty typical.

The OIII is a very limited band width and the nebulosity may have been too faint.... They can help with larger scope to "pull" out faint detail and are good for the identification of planetary nebula..other than than they are more useful for imaging.

[twotter]

The first time I used my OIII filter I was surprised how dark the view was too. But, on the right target, it changes the view completely...the Veil Nebula stood out and was quite stunning

[mylatestwhim]

Thanks guys much 'clearer' now

I'll have to get nebula hunting and have a play